1. Technical Field
Disclosed herein are methods and systems to implement and operate modular software-defined radios (SDRs), including SDRs for terrestrial and extraterrestrial use.
2. Related Art
Software-defined radios (SDRs) arose in the late 1970s in the defense sector. The term “software-defined radio” has been in use since at least 1991. An early U.S. military SDR initiative, named SpeakEasy, sought to use programmable processing to emulate multiple existing military radios operating in frequency bands between 2 and 2000 MHz, and to enable incorporation of new coding and modulation techniques in the future.
SDR development is driven predominantly by terrestrial needs, including military and emergency response needs, such as to provide interoperability amongst different equipment. For example, the U.S. military has developed a Joint Tactical Radio System to provide flexible and interoperable communications amongst hand-held, vehicular, airborne, dismounted, fixed base-station, and maritime radios.
Extraterrestrial environments present challenges that may not be encountered to the same degree in terrestrial environments, such as physical inaccessibility, higher signal propagation frequencies, radiation, relatively vast distances between transmitters and receivers, different mission requirements, and more onerous limitations on size, mass, and power consumption.
Designs developed for terrestrial applications are not necessarily suitable for extraterrestrial environments, and do not necessarily satisfy extraterrestrial challenges. Limited resources allotted for extraterrestrial programs may necessitate unconventional configurations of commercially available components, rather than design and manufacture of new components.